The present invention involves a type of nanoporous macrocycle-containing cross-linked polymeric membrane, a method of making the membrane, and the use of such a novel membrane system for natural gas liquids (NGL) recovery, fuel gas conditioning, natural gas pre-treatment, sulfur removal from fluidized catalytic cracking (FCC) and other naphtha streams, as well as aromatic separations such as aromatic/paraffin separation and xylene separation. The nanoporous macrocycle-containing cross-linked polymeric membrane is prepared from a diisocyanate-terminated polyether or a diisocyanate-terminated polyester, that is crosslinked with a nanoporous macrocycle comprising hydroxyl functional groups such as α-, β-, and γ- cyclodextrins.